IAEA FUMAC Benchmark on KIT Bundle Test CORA-15

In framework of the FUMAC/IAEA project, a benchmark has been performed on the CORA-15 bundle test performed at KIT. Two organizations have provided results for this modelling: GRS/Germany (ATHLET-CD code applied) and IBRAE/Russia (SOCRAT code applied). In the test, the behaviour of the PWR type fuel bundle, composed of 23 fuel rods and 2 absorber rods, was investigated under severe accident conditions. An important feature of the experiment in difference to all other CORA bundle tests was the pressurization of fuel rods to 6 MPa. As a result, the fuel rods underwent ballooning and burst. In general, both codes adequately reproduced the cladding temperatures evolutions, its ballooning and rupture, and the blockage formation due to melt relocation. The hydrogen release has been calculated within the uncertainty of the measured data.